Core barrel



June 5, 1951 c. L. DEELY 2,555,580

CORE BARREL Filed Nov. 14, 1947 INVENTORQ Calm/ll. flee/y B Y WWW Patented June 5, 1951 UNITED STATES PATENT OFFICE CORE BARREL Carroll L. Deely, Dallas, Tex.

Application November 14, 1947, Serial No. 786,058

11 Claims. 1

This invention relates to improvements in core barrels, and more particularly to core barrels of the type which are used for receiving a core cut in the earth strata during the drilling of a well.

In my prior application on Core Barrels, Serial 653,752, filed March 12, 1946, now Patent No. 2,490,512, I have provided a core barrel having an inner tube swiveled with respect to the main or outer core barrel adapted to receive the core therein and to remain non-rotatable with respect to the core during the rotation of the outercore barrel in cutting a core in the earth strata. It was provided in such construction for circulating a drilling fluid downward through the core barrel outside the inner core tube to facilitate the cutting action. Such a drilling fluid would have access to the swiveling means for the inner tube, and I have found that it interfered with the proper swiveling action.

The object of this invention is to improve the construction of the core barrel and particularly to exclude mud from the swiveling means for the inner core tube while lubricating the bearings thereof, and thereby insure of easy operation of the device without interference to the swiveling action by the presence of the mud.

This object may be accomplished according to one embodiment of the invention by enclosing the bearings within a suitable lubricant confined in a chamber which will exclude the mud and insure of smooth and uniform operation for an extended period of service. A seal is provided on one side of the bearings at the open end of the bearing housing confining the lubricant between the seal in the housing against a flexible diaphragm of yieldable material, preferably of rubber or rubberlike material that is sufficiently elastic for the purpose and which will respond to the introduction of lubricant into the chamber and apply a pressure thereto to insure of uniform and proper lubrication of the bearings and to exclude mud from the bearing housing during the operation of the core barrel.

This embodiment of the invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical sectional view through the upper end portion of the core barrel;

Fig. 2 is a similar view through the lower end portion thereof;

Fig. 3 is a cross section through the core barrel on the line 3--3 in Fig. 1;

Fig. 4 is a similar view therethrough on the line 4-4 in Fig. 1;

Fig. 5 is a similar View therethrough on the line 5-5 in Fig. 1; and

Fig. 6 is a perspective view of the diaphragm, removed.

The invention is shown applied to a core barrel, generally of the structure set forth in my prior application, Serial No. 653,752, filed March 12, 1946, wherein provision was made for swiveling a portion of the core barrel to hold the core in place therein while allowing rotation of the main core barrel in cutting the core from the strata.

As shown in the drawings, the core barrel is designated generally by the numeral l and is provided with a bit 2 on the lower end thereof, which may be of the conventional diamond cutting bit customarily used or of other construction suitable for the purpose. The upper end of the core barrel is secured to a head 3 internalh threaded to provide a pipe joint 4 adapted for connection of a string of drill pipe therewith for rotation of the tool.

The head 3 has a depending portion, designated generally at 5, telescoped into the upper end of the core barrel l and spaced from the inner wall thereof. This depending portion 5 supports a I sleeve 6 having internal screw-threaded connection therewith, and the sleeve 6 is coupled with a bearing housing 7. Mounted in the bearing housing 1 are anti-friction bearings 8 upon which is supported a shaft 9 held in place by a swivel nut ll! seated upon the topmost bearing and threaded on the shaft. The shaft 9 extends downwardly from the lower end of the bearing housing 1 and supports a core tube H on the depending lower end thereof, which core tube is adapted to receive the core cut by the bit 2, and has a core catcher l2 in the lower end thereof to confine the core in the tube l I when separated from the earth, substantially as described in my application referred to above.

The core tube I l is supported on the shaft 9 by a coiled spring l3 sleeved over the lower end portion of the shaft and confined by a nut l4 threaded thereon, the coiled spring l3 being interposed between the nut M and the closed. upper end of the core tube H. The shaft 9 has an axial passage l5 therethrough with a radial discharge opening lfi to direct air and fluid out of the core tube as the core gradually is received therein.

This forms a swiveled support for the core tube II on the bearing housing 1 which in turn is suspended from the head 3. It is adapted to receive the core in the core tube as the core is cut from the earth strata by the rotary movement of the core barrel l and bit 2 in the normal act of rotating the drill stem for this purpose. This drilling operation includes the downward circulation of drilling fluid through the drill stem and through the central opening of the head 3, from which it is circulated through radial passages ll formed in the head into the space between the core barrel I and the bearing housing 1, which space is annular in form as shown in Figs. 4 and 5 and is designated generally at It.

The lower end of the bearing housing is closed by grease seals generally indicated at iii, any suitable form of which may be used as desired, of which several forms are well known in the trade. These grease seals close the space between the bearing housing and the periphery of the swivel shaft 9 to prevent the admittance of drilling fiuid or mud from the space l8 into the lower end of the bearing housing 1, and thereby confine the bearings against the access of fluid thereto.

Provision is made, preferably, for lubricating the bearings by a suitable grease or other lubricant, not only to exclude fluid therefrom, but also to provide the desired free swiveling action of the core barrel. Such grease may be enclosed in a chamber 2:: within the sleeve 6 at the top of the bearings 8 in open communication there with, and be supplied thereto through a lubricant fitting 25 in a side of the sleeve 6, which fitting may be of any well known character suitable for the purpose.

It is preferred'that the top of the chamber 2Q be closed by a diaphragm 22 having its periphery 23 clamped between the upper end of the sleeve 6 and a shoulder 24 formed in the lower portion of the head 3. The purpose of the dia phragm is to respond to the pressure differential between the inside of the chamber 26 in the bearing housing l and the hydrostatic pressure in the hole as communicated thereto through the passage IS. The diaphragm functions to close the upper end of the chamber against entrance of mud or the loss of lubricant, and to provide a flexible surface upon 'which the hydrostatic pressure may react to keep a pressure on the grease within the chamber to prevent the entrance of drilling fluid or mud into the chamber 28 past the seals I9. Due to the restricted annular space 18 between the passages l'l and the lower end of the swivel housing I, a slightly greater pressure is exerted on the diaphragm 22 than on the seals 59. Therefore, the grease within chamber will have a tendency to be forced outward past the seals l9, lu-' bricating the same and preventing the entrance of mud.

Unless all of the air is eliminated from the grease, the diaphragm may break and allow the fluid to enter the chamber 26. To work most eiiiciently, all of the air possible should be removed from the chamber 20, as the differential of pressure of the drilling fluid existing between the seals as and the diaphragm 22 would cause the diaphragm to flex the maximum degree, if not removed, without exerting sufiicient push on the grease to keep the seals l9 lubricated and keep the mud out of the chamber 26.

. This may be accomplished by loosening the connection between the sleeve i: and depending portion 5 as the chamber 20 is initially filled with grease through the fitting 2|, allowing the air to escape therefrom through orifices or air vents (see Fig. 5), after which these parts are connected securely together, and the periphery 23 of the diaphragm is clamped tightly between the surfaces at the end of the sleeve 6 and the shoulder 2t, which surfaces may be provided with circumferential ribs or grooves to insure of a sealing action on the periphery of the diaphragm. It will not be necessary to remove the air again after the initial filling of the chamber.

Before filling with lubricant, the diaphragm is normally in the position shown in dotted-lines in Fig. 1, but the pressure built up in applying grease to the chamber 26 forces the diaphragm up to the full-line position in Fig. 1. As the grease is used, the diaphragm gradually shifts downwardly from the full-line position.

The outer face of the diaphragm 22 is subjected to the hydrostatic pressure of the fluid being circulated through the space l8 or the fluid in the well, through orifices 26 that extend radially'through the depending portion of the head 3, as shown in Figs. 1 and 4. Thus the hydrostatic pressure in the well will be applied through thediaphragm to the grease, tending to main tain a sufficient pressure thereon to lubricate the bearings and to exclude mud and other fluid from the lower end of the bearing housing. This will allow a free and. smooth swiveling action of the core barrel relative to the core tube H without interference of the mud or other fiuid to the freedom of such swiveling action, and maintaining an adequate lubrication of the bearings thereof.

While the invention has been illustrated and described in one embodiment, it is recognized that variations and changes may be made therein without departing from the invention except as specified in the claims.

I claim:

1. A well drilling device comprising a core barrel, a head connected with the upper end portion of the core barrel, a core tube within the barrel, a shaft supporting the core tube, a housing supported by the head and surrounding the shaft, bearing means mounting the shaft in the housing, and means for sealing the bearing means against the admission of fiuid thereto from between the core barrel and the core tube, a lubricant chamber formed within said head and in open communication with said bearing means, a pressure responsive element having one side in communication with said lubricant chamber and its opposite side positioned so as to be in com-v munication with a source of hydrostatic pressure, and means for applying such hydrostatic pressure to said opposite side of the element during the drilling operation so that pressure will be maintained on the lubricant in said lubricant chamber to keep the bearing members fully supplied and to oppose the entry of drilling fluid through said sealing means.

2. A well drilling device comprising a core barrel, a housing adapted to enclose a lubricant containing chamber and connected with the upper end portion of the core barrel, a core tubewithin the barrel, a shaft supporting the core tube, bearing means in the housing rotatably supporting said shaft therein, and means for sealing the bearing means against the admission of fluid thereto from between the core barrel and'thecore tube, said sealing means including a lubricant chamber in said housing in open communication with the bearing means to supply lubricant thereto and for excluding mud therefrom, and;

means responsive to the pressure of the drilling fluid for exerting pressure on the lubricant in, I

said lubricating chamber to urge the lubricant into intimate contact with said bearings.

'3. A well drilling device comprising a core barrel, a head connected with the upper end portion ofthe core barrel, a core tube within the barrel, a shaft supporting the core tube, a housing supported by the head and surrounding the shaft, bearing means mounting the shaft in the housing, and means for sealing the bearing means against the admission of fluid thereto from between the core barrel and the core tube, said sealing means including a lubricant chamber formed in said housing in open communication with the bearing means to supply lubrication thereto and for excluding mud therefrom, and a resilient diaphragm closing a side of said chamber to exclude mud therefrom and in position to apply yielding pressure to the lubricant therein.

4. A well drilling device comprising a core :barrel, a head connected with the upper end portion of the core barrel and constructed for circulating drilling fluid downwardly therethrough, a core tube within the barrel, a shaft supporting the core tube, a housing surrounding the shaft, antifriction bearings mounted in the housing and journaling the shaft therein, means for suspending the housing from the head, means for sealing the lower end portion of the housing externally of the shaft against the admittance of fluid to the bearings therethrough, said housing having a chamber therein above the bearings for confining lubricant in communication with the bearings, and a diaphragm closing the upper end portion of said chamber and sealing the chamber against the admittance of fluid thereto.

5. A well drilling device comprising a core barrel, a head connected with the upper end portion of the core barrel and constructed for circulating drilling fluid downwardly therethrough, a core tube within the barrel, a shaft supporting the core tube, a housing surrounding the shaft, anti-friction bearings mounted in the housing and journaling the shaft therein, means for suspending the housing from the head, means for sealing the lower end portion of the housing externally of the shaft against the admittance of fluid to the bearings therethrough, said housing having a chamber therein above the bearings for confining lubricant in communication with the bearings, and a diaphragm closing the upper end portion of said chamber and sealing the chamber against the admittance of fluid thereto, said diaphragm being of resilient material for applying pressure to the lubricant in the chamber, and means for admitting fluid to the exterior surface of the diaphragm for applying hydrostatic pressure thereto.

6. A well drilling device comprising a core barrel, a core tube in the core barrel adapted to receive a core therein, a shaft supporting said core tube, a head connected with the core barrel, bearing means journaling the shaft on the head for relative swiveling action between the core barrel and the core tube, a lubricant chamber formed within said head and in communication with said bearing means, sealing means between said head and said shaft for effecting a seal against admission of fluid into said bearing means between said head and said shaft, means for introducing lubricant into said lubricant chamber while said shaft and said bearing means are in assembled relation, and a pressure responsive element interposed between said lubricant chamber and a source of pressure so said pressure responsive element will maintain pressure on said lubricant in 6 said lubricant chamber and on said bearing means during the drilling operation.

'7. A well drilling device comprising a core barrel for use with a hydraulic drilling fluid in a well, a head connected with the upper end portion of said core barrel and forming a housing, a core tube within said core barrel, a shaft supporting said core tube, bearing means mounting the shaft within said housing, means for sealing the bearing means against admission of fluid thereinto between said shaft and said housing, a lubricant chamber formed in said housing in open communication with said bearing means, means for supplying a lubricant to said lubricant chamber, a movable element responsive to the hydrostatic pressure of the drilling fluid for directing lubricant from said lubricant chamber into said bearing housing.

8. A well drilling device comprising-a core barrel .for use with a hydraulic drilling fluid in a well, a head connected to the upper end portion of said core barrel and extending within said core barrel and peripherally spaced from the walls of said barrel, a housing within said head, bearing means mounting a shaft within said housing for supporting a core tube, means for sealing the bearing means against admission of fluid into said housing between the shaft and said housing and to prevent escape of lubricant therefrom under normal operating conditions, a lubricant chamber formed in said housing in open communication with said bearing means, means for supplying lubricant to said lubricant chamber, a movable element responsive to the hydrostatic pressure of said drilling fluid so as to maintain said lubricant in said lubricant chamber and in said bearing housing at a pressure substantially equal to that of said drilling fluid upon the reaction of hydrostatic pressure of said drilling fluid upon said movable element.

9. A well drilling device comprising two nested hollow cylindrical members, said members comprising a core barrel and a core tube carried within said barrel and adapted to receive a core, means within the upper portion of said barrel for rotatably suspending said core tube, said suspending means comprising a housing carried by one of said members and a longitudinally extending shaft carried by the other of said members and extending into said housing, said housing enclosing a lubricant containing chamber, thrust bearing means in the chamber within said housing and journalling said shaft therein, means for introducing lubricant into said chamber, sealing means between said shaft and said housing at at least one end of the latter tending to prevent loss of lubricant and entry of drilling fluid, and a pressure responsive member having one side in communication with the body of lubricant in said chamber and the other side exposed to a source of hydrostatic pressure.

10. A well drilling device comprising two nested hollow cylindrical members, said members comrising a core barrel and a core tube carried within said barrel and adapted to receive a core, means within the upper portion of said barrel for rotatably suspending said core tube, said suspending means comprising thrust bearing means, a casing enclosing said bearing means and providing a lubricant chamber therefor, a body of lubricant in said chamber, sealing means preventing the escape of lubricant and the entry of drilling fluid to said chamber, said sealing means including a movable wall portion of the casing, and means for subjecting the outer surface of said movable wall portion to hydrostatic pressure to exert pressure on the body of lubricant in said chamber to urge the lubricant into intimate contact with said bearings.

11. A well drilling device comprising two nested hollow cylindrical members, said members comprising a core barrel and a core tube carried within said barrel and adapted to receive a core, means within the upper portion of said barrel for rotatably suspending said core tube, said suspending means comprising thrust bearing means, a casing enclosing said bearing means and providing a lubricant chamber therefor, a body of lubricant in said chamber, sealing means preventing the escape of lubricant and the entry of drilling fluid to said chamber, said sealing means including a packing device at one side of said casing and a movable wall portion of the casing on the opposite side of the bearings from the position of said packing device, and means for subjecting the outer surface of said movable wall portion to hydrostatic pressure to exert pressure on the body of lubricant in said chamber to urge the lubricant into intimate contact with said bearings.

CARROLL L. DEELY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

